Belt conveyors are commonly used in the mining industry for conveying particulate material such as mined materials for example coal or ore. Conveyors of this type include a moving belt for carrying the material to be conveyed supported on a plurality of sets of conveyor idler rollers. The conveyor idler roller sets usually include two or more idler rollers arranged in an end-to-end relationship. In one particular arrangement, the conveyor idler roller sets include a central roller and side rollers on opposite sides of the central roller. The conveyor idler sets further include a support frame provided with spaced notched brackets or lugs to receive the opposite ends of axles of the idler rollers. The brackets may be configured to support the rollers at an obtuse angle relative to each other or where there is a central roller and opposite side rollers, the side rollers at an obtuse angle to the central roller so that the belt supported on the rollers forms a concave dish-shape in cross section. Some conveyor idler sets have provision to vary the angle between the respective rollers by providing a plurality of mounting points for the roller axles. The rollers thus may be adjusted between one position in which they are axially aligned and in which the belt supported thereon is substantially planar to other positions where the rollers are inclined such that a belt supported thereon has the concave dish- or trough-like configuration.
Removal of an idler from the conveyor idler roller sets of the above described type for replacement or service presents a number of difficulties. In many cases, it is necessary to stop the operation of the conveyor so that access can be had to the conveyor idler sets. Furthermore, idler replacement on idler sets at elevated locations usually requires a workman to wear a safety harness and may require more than one person to work on the idler set during this procedure. Furthermore, on ground mounted structures, a workman is required to lie under the return line of the conveyor belting which is not desirable from the point of health and safety requirements or legislation. A workman may also be required to lie inside the conveyor structure to replace the central idler rollers which can also be unsafe.